A Normalized Global Economic Policy Uncertainty Index from Unsupervised Machine Learning

In this work, we integrate the conventional unsupervised machine learning algorithm—the Principal Component Analysis (PCA) with the Random Matrix Theory to propose a novel global economic policy uncertainty (GPEU) index that accommodates global economic policy fluctuations. An application of the Ran...

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Main Authors: Wangfang Xu, Wenjia Rao, Longbao Wei, Qianqian Wang
Format: Article
Language:English
Published: MDPI AG 2023-07-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/11/15/3268
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author Wangfang Xu
Wenjia Rao
Longbao Wei
Qianqian Wang
author_facet Wangfang Xu
Wenjia Rao
Longbao Wei
Qianqian Wang
author_sort Wangfang Xu
collection DOAJ
description In this work, we integrate the conventional unsupervised machine learning algorithm—the Principal Component Analysis (PCA) with the Random Matrix Theory to propose a novel global economic policy uncertainty (GPEU) index that accommodates global economic policy fluctuations. An application of the Random Matrix Analysis illustrates the majority of the PCA components of EPU’s mirror random patterns that lack substantial economic information, while the only exception—the dominant component—is non-random and serves as a fitting candidate for the GEPU index. Compared to the prevalent GEPU index, which amalgamates each economy’s EPU weighted by its GDP value, the new index works equally well in identifying typical global events. Most notably, the new index eliminates the requirement of extra economic data, thereby avoiding potential endogeneity in empirical studies. To demonstrate this, we study the correlation between gold future volatility and GEPU using the GARCH-MIDAS model, and show that the newly proposed GEPU index outperforms the previous version. Additionally, we employ complex network methodologies to present a topological characterization of the GEPU indices. This research not only contributes to the advancement of unsupervised machine learning algorithms in the economic field but also proposes a robust and effective GEPU index that outperforms existing models.
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spelling doaj.art-2de14cc1819641d8860fc10e85a4f82e2023-11-18T23:14:23ZengMDPI AGMathematics2227-73902023-07-011115326810.3390/math11153268A Normalized Global Economic Policy Uncertainty Index from Unsupervised Machine LearningWangfang Xu0Wenjia Rao1Longbao Wei2Qianqian Wang3China Academy for Rural Development, Zhejiang University, Hangzhou 310058, ChinaSchool of Science, Hangzhou Dianzi University, Hangzhou 310018, ChinaChina Academy for Rural Development, Zhejiang University, Hangzhou 310058, ChinaSchool of Economics and Management, Zhejiang Sci-Tech University, Hangzhou 310018, ChinaIn this work, we integrate the conventional unsupervised machine learning algorithm—the Principal Component Analysis (PCA) with the Random Matrix Theory to propose a novel global economic policy uncertainty (GPEU) index that accommodates global economic policy fluctuations. An application of the Random Matrix Analysis illustrates the majority of the PCA components of EPU’s mirror random patterns that lack substantial economic information, while the only exception—the dominant component—is non-random and serves as a fitting candidate for the GEPU index. Compared to the prevalent GEPU index, which amalgamates each economy’s EPU weighted by its GDP value, the new index works equally well in identifying typical global events. Most notably, the new index eliminates the requirement of extra economic data, thereby avoiding potential endogeneity in empirical studies. To demonstrate this, we study the correlation between gold future volatility and GEPU using the GARCH-MIDAS model, and show that the newly proposed GEPU index outperforms the previous version. Additionally, we employ complex network methodologies to present a topological characterization of the GEPU indices. This research not only contributes to the advancement of unsupervised machine learning algorithms in the economic field but also proposes a robust and effective GEPU index that outperforms existing models.https://www.mdpi.com/2227-7390/11/15/3268global economic policy uncertainty indexprincipal component analysisrandom matrix theorycomplex networkGARCH-MIDAS modelfuture price volitility
spellingShingle Wangfang Xu
Wenjia Rao
Longbao Wei
Qianqian Wang
A Normalized Global Economic Policy Uncertainty Index from Unsupervised Machine Learning
Mathematics
global economic policy uncertainty index
principal component analysis
random matrix theory
complex network
GARCH-MIDAS model
future price volitility
title A Normalized Global Economic Policy Uncertainty Index from Unsupervised Machine Learning
title_full A Normalized Global Economic Policy Uncertainty Index from Unsupervised Machine Learning
title_fullStr A Normalized Global Economic Policy Uncertainty Index from Unsupervised Machine Learning
title_full_unstemmed A Normalized Global Economic Policy Uncertainty Index from Unsupervised Machine Learning
title_short A Normalized Global Economic Policy Uncertainty Index from Unsupervised Machine Learning
title_sort normalized global economic policy uncertainty index from unsupervised machine learning
topic global economic policy uncertainty index
principal component analysis
random matrix theory
complex network
GARCH-MIDAS model
future price volitility
url https://www.mdpi.com/2227-7390/11/15/3268
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